Price-indicating balance



July 24, 1928. 1,678,153

K. MARTIN PRICE INDICATING BALANCE Filed Ju'iv 14 19% 2 Sheets-Sheet 1 mil July 24, 1928. 1,678,153

. Y K. MARTIN PRICE INDI CATING BALANCE Filed July 14, 1926 2 Sheets-Sheet 2 Patented July 24, 1928.

UNITED STATES KARL MARTIN, OF RATHEN OW, GERMANY.

PRICE-IN DICATIN G BALANCE.

Application filed July 14, 1926, Serial No. 122,491, and in Germany July 1, 1925.

This invention relates to price indicating balances.

The very useful needle balances are recently employed on a large scale, with which the Weight of the merchandise can be read off on a dial. Furthermore, balances are well known which indicate at the same time the price of the weighed quantity. This problem has been tried to be realized in the simplest form, by arranging below the scale of the weights a big table which contains a the products of the individual weights and units prices. The needle which indicates the weight on the main scale moves at the 1 same time before this price table and enables the price to be read. off in each column of amounts.

This reading-off operation, however, is diflicult, as the table showing the numeral values must have a very large extent, and errors will thus easily arise. By this reason balances have been constructed, with which the price of the weighed quantity is exhibited immediately, but balances of this type are of course very complicated in structure.

Now my invention has for its object to.

have a device which makes it possible to ascertain the 'price of the weighed quantity 39 of merchandise in a very simple manner and offering at the same time the advantage that it can be applied to existing balances having only a scale of weights. This problem is realized according to my invention, 85 by ofiering to the eye of the selleror customer, besides or instead of the scale of weights the needle plays before, by subjectively or objectively acting optical means, the image of a price scale, said last named 40 scale being able to be altered in a very simple manner. The image of a price scale is projected, either subjectively or objectively, to the indicating side of the balance, and this in such a manner that the needle of the balance or an image of this needle makes indications on this price scale image too.

In order to make my invention more easily understood, two embodiments of the subject-matter of the same are diagrammatically illustrated by way of example in the drawings which accompany and form part of this specification. On these drawings:

Fig. 1 shows the device enabling objective 1 projection,

"on the lower, one by means of said needle.

Fig. 2 the device enabling subjective proection,

Fig. 3 shows a rotary price scale carrier used with these embodiments,

Figs. 4 and 5 are two enlarged views of the scale of weights with a price scale prodifferent price scales ;0 arranged on small glass plates. V

As to be seen from Fig. 1, a lamp illumlnates the scale 10 just inserted into the field of view and projects it through the lens 0 to the .scale s, a condensing lens being interposed in this optical system. By interposing further a light filter f it ispossible to project the price scale for instance in red color, whereas the scale of weights is black, so that both said scales may be clearly distinguished. The image produced on the scale of weights has about the aspect illustrated in Fig. 4. As a matter of course, the zero points of both said scales must be adjusted so as, to register correctly. Upon the deflection of the needle 2, the weight can be read off on the upper scale, and the price In accordance with the different prices a corresponding plurality of price scales 3) must be arranged on the rotary carrier 1'. This carrier, however, needs not to have exceedingly large dimensions, as, with a suitable selection of the described optical system but very small price scales 2? are required which are projected to the weight scale s with a suitably high magnification.

In the embodiment illustrated said price scales are shown, for the sake of clearness, in a comparatively large size.

As it will clearly be seen from the drawing, there is noconstructive connection between the inner' structure of the balance and the described price indicating device, so that this device may easilybe constructed as a supplement and combined with each existing needle balance.

In the embodiment illustrated in Fig. 2 the subjective. projection is employed. Here the object glass 0 projects an image of the needle 2, and under certain-circumstances also of the scale 8, into its plane of image, wherein the interchangeable prlce made use of, which has to be projected with thereof, and this single scale nified correspondingly by optical means,

difierent magnifications. Evidently the spaces existing between the division lines of the scale are inversely proportional to the units prices they symbolize, that means with double units prices said spaces must have half size. Now, as it does not offer any difliculty in optical respects to produce images of difl'erent size of an object like said price scale, the described devices need to have but one single price scale instead of a rotar carrier com risin a luralit y P t P]O Y as o e magaccount having to be taken of the individual units price of 1 kg. I

Figs. 4 and 5 illustrate the aspect offered to the operators eye when the price scales p are visible together with the weight scale s and needle 2 in diiferent magnification, that of, Fig. 5 being double that of Fig. 4, that means theprice scaleof Fig. 5 refers to 9.

:price of 1 kg. of half the amount of that of ig. 4. a

There may of course be two such devices on a balance so that the price of the merchandise may be read off simultaneously by the seller and the customer.

I claim:

1. In a balance having a weight-indicating scale and a needle co-operating therewith, an independent transparent price-indicating scale, a source of light, a system of lenses arranged co-axially. thereto, said scale being disposed in the course of the light-rays pass.

ing through said lenses, the image of said price indicating scale being projected by said system of lenses into cooperative relation to said needle.

2. In a balance having a weight-indicating scale and a needle adapted to move over said scale, a seriesof price-indicating scales remote from said weight-indicating scale, and optical means for bringin said needle and weight-indicating scale an any one of said series of price-indicating scales into a common field of vision, with said needle and price-indicating scale in superposed relation and said price and Weight-indicating scalesn such proximity that the price and weight indicated by said needle can be read practlcally simultaneously. In testimony whereof the foregoing spec fication is signed. I

- KARL MARTIN. 

